Epoxide taurine condensation products and detergent compositions containing them

ABSTRACT

NOVEL CONDENSATION PRODUCTS WHEREIN A C3-C5 ALIPHATIC EPOXIDE AND A C3-C18 ALIPHATIC EPOXIDE ARE CONDENSED WITH TAURINE, AND BUILT SYNTHETIC DETERGENT COMPOSITIONS WHEREIN AT LEAST A PORTION OF THE SODIUM TRIPOLYPHOSPHATE IS REPLACED BY THIS EPOXIDE-TAURINE CONDENSATION PRODUCT.

United States Patent O EPOXIDE TAURINE CONDENSATION PRODUCTS AND DETERGENT COMPOSITIONS CONTAIN- ING THEM Robert M. Lincoln, Moylan, and Joseph A. Meyers III, Springfield, Pa., and Richard W. Sauer, Cherry Hill, N.J., assignors to Atlantic Richfield Company, New York, N.Y.

No Drawing. Continuation-impart of application Ser. No.

625,281, Mar. 23, 1967, which is a continuation-inpart of application Ser. No. 548,876, May 10, 1966. This application Apr. 2, 1969, Ser. No. 812,919

Int. Cl. C11d 3/34 US. Cl. 252137 3 Claims ABSTRACT OF THE DISCLOSURE Novel condensation products wherein a C -C aliphatic epoxide and a C -C aliphatic epoxide are condensed with taurine, and built synthetic detergent compositions wherein at least a portion of the sodium tripolyphosphate is replaced by this epoxide-taurine condensation product.

CROSS REFERENCES TO RELATED APPLICATIONS This application is a continuation-in-part of our copending application, Ser. No. 625,281 filed Mar. 23, 1967, entitled Epoxide Taurine Condensation Products and Detergent Compositions Containing Them, now abandoned, which, in turn, is a continuation-in-part application of our application, Ser. No. 548,876, filed May 10, 1966, entitled Built Synthetic Detergent Compositions, now abandoned.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to acyclic sulfonic acids and salts thereof and more particularly to the products from the condensation of a C -C aliphatic epoxide and a C C aliphatic epoxide with taurine to produce the corresponding N-substituted beta-hydroxyalkyl taurides and to synthetic detergent compositions containing N-substituted beta-hydroxyalkyl taurides as a partial or complete replacement for the sodium tripolyphosphate in synthetic detergent compositions.

DESCRIPTION OF THE PRIOR ART The use of polyphosphates such as sodium tripolyphosphate as builders in commercial synthetic detergent formulations has become almost universal because of their synergistic action in such formulations. Although the polyphosphates are perhaps most widely used in alkylbenzenesulfonate type detergents they are also used in combination with alkyl sulfates and in formulations containing both anionic and non-ionic surfactants.

The action of the polyphosphates in their effect on detergency is many-fold. They reduce redeposition of soil particles by protective colloid action or deflocculation action, they saponify glyceride-type soils and act as bufiering agents to prevent the released fatty acids from lowering the pH of the detergent solution. They also function as neutralization agents for acidic soils and behave as sequestering agents or water-softening agents in hard water solutions. The polyphosphates, therefore, are extremely important in detergent formulations.

There has been gathered a considerable amount of evidence in recent years which indicates that the phosphates provide an environment which promotes excessive algae formation in surface waters such as ponds, streams, rivers, lakes and the like. While the phosphates may come from a number of sources, for example, the run-off from phosphate fertilized fields, the polyphosphates which have been utilized in synthetic detergent formulations also undoubtedly contribute to the overall phosphate contamination. Consequently, there has been a considerable amount of work carried on to find compounds which can be utilized to replace all or at least a part of the polyphosphates in detergents.

One group of compounds which have been tested for this purpose in accordance with this invention are the epoxy taurine condensation roducts. The condensation of chlorinated higher aliphatic alcohols with taurine or N-alkyl substituted taurine to produce epoxy taurides has been known for a number of years and it has also been suggested that these compounds be utilized as lathering agents or wetting-out agents.

SUMMARY OF THE INVENTION It now has been found that the condensation product of certain epoxides with a taurine salt or with an N methyl taurine salt can be combined with certain inorganic salt buffering agents and the combination can be substituted for a part or all of the polyphosphates in a synthetic detergent formulation and provide the same functions in the formulation as the polyphosphates pro vide.

It is an object of this invention therefore to provide a synthetic detergent formulation wherein a portion or all of the polyphosphates has been replaced by non-phosphate compounds.

It is another object of this invention to provide a synthetic detergent formulation wherein a combination of an epoxide-taurine salt condensation product with inorganic salt buffering agents are substituted for at least a portion of the polyphosphate content of the detergent formulation.

Other objects of this invention will be apparent from the description and claims that follow.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In accordance with this invention novel sulfonic acids and salts thereof are produced by the condensation of a C -C aliphatic epoxide and a C -C aliphatic epoxide with taurine to give the corresponding N-substituted betahydroxy alkyl taurides. Further, in accordance with this invention these salts are combined With the salt of a strong base and a weak acid and the combination is used to replace a part or all of the sodium tripolyphosphate in a synthetic detergent formulation, the other components of the formulation being unchanged. There are certain standard detergent formulations widely used in the industry. One consists of the following ingredients in weight percent: sodium tripolyphosphate35; alkylbenzenesulfonate-20; sodium metasilicate7; sodium sulfate-37 and sodium carboxy methyl cellulosel. Another formulation frequently used in the industry consists of the following ingredients in weight percent: sodium tripolyphosphate-40; alkylbenzenesulfonate--20; sodium metasilicate7; sodium sulfate-31 and sodium carboxy methyl cellulose-2.

It has been found in accordance with this invention that a part or all of the sodium tripolyphosphate in such formulations can be replaced by the novel epoxide taurine salts of this invention in combination with inorganic salt bufiering agents, i.e. salts of a strong base and a weak acid. Although the compounds of this invention can be used to replace any part or all of the sodium tripolyphosphate on a weight for weight basis, it is preferred to replace at least 50 percent of the sodium tripolyphosphate and it is most preferred to replace substantially all of the sodium tripolyphosphate since it is an object of the invention to eliminate polyphosphates from built detergents because of their undesirable properties in surface waters.

It has been found that the weight ratio of the epoxide taurine condensation product to the inorganic salt bufiering agent may range from 1:3 to 1:7 or expressed difien ently, from about 12.5 weight percent to 25 weight percent of the polyphosphate content is replaced by the epoxide taurine condensation product and the remaining 87.5 weight percent to 75 weight percent of the polyphosphate content is replaced by the inorganic salt buttering agent. Likewise, other detergent formulations such as those wherein a sulfonate is produced from an alpha olefin may be modified by the elimination or a part or all of the phosphate content of the formulation and the replacement of that amount eliminated with the same amount by weight of the combination of the epoxide taurine condensation product and the inorganic salt in the same ratios which have been described.

The epoxide taurine salt condensation products which are used in this invention have the farmula wherein R is an alkyl radical having from 1 to 16 carbon atoms, R is hydrogen or an alkyl radical having from 1 to 15 carbon atoms, the sum of the carbon atoms in R plus R ranges from 2 to 16, M is ammonium or an alkali metal ion and R is a methyl radical, an ethyl radical or a propyl radical. These compounds are produced by the condensation of the taurine salt with the C to C epoxide and thereafter condensing the C -C epoxide taurine salt condensation product with an epoxide having from 3 to 18 carbon atoms.

These diepoxide taurine salt condensation products can be produced by reacting the C to C epoxide with a taurine salt such as the sodium salt in the presence of water. Although the sodium salt is the most convenient salt, other alkali metal or ammonium salts of taurine can be employed. Since this reaction is a condensation reac tion reaction it is preferred to employ approximately equal molar quantities of the reactants although an excess of either reactant may be used without affecting the reaction. This first condensation step is very rapid and is exothermic and, in general, is substantially quantitative, i.e. a theoretical yield of the condensation product is very rapid and is exothermic and, in general, is substantially quantitative, i.e. a theoretical yield of the condensation product is obtained. Evaporation of the water gives the N-beta-hydroxy C -C alkyl taurine salt. Equal molar quantities of this taurine salt condensation product is then reacted with an alkyl epoxide having from 3 to 18 carbon atoms in the molecule. It is preferred to employ a small amount of base such as aqueous sodium hydroxide together with temperature of the order of 80 C. to 120 C. with a reaction time of from 4 to 6 hours in carrying out this second condensation step. The final condensation product consisting of the N-beta-hydroxy C -C alkyl-N-beta-hydroxy C C alkyl taurine salt is recovered by partioning between a hydrocarbon solvent such as n-hexane and a polar solvent such as methyl alcohol. The final condensation product is obtained from the methyl alcohol layer by evaporation of the solvent. These diepoxide-taurine salt condensation products have the formula set forth above.

The inorganic salt buffering agent is the salt of a strong base and a weak acid, for example sodium metasilicate, sodium carbonate, sodium bicarbonate, sodium acetate, ammonium carbonate and the like. Sodium metasilicate and sodium carbonate are preferred primarily because of their low cost.

The combination of compounds of this invention can be used to replace the polyphosphates in detergent formulations wherein the surfactant is an anionic surfactant or a nonionic surfactant or a mixture of these. For example, the anionic may be an alkylbenzenesulfonate wherein the alkyl radical is either branched chain (the hard or difficulty biodegradable surfactant), or a straight chain (the soft or readily biodegradable surfactant). The surfactant also may be other well-known commercial anionic compounds such as the alcohol sulfates or alkyl sulfonates or it may be a mixture of the alcohol sulfate or alkyl sulfonate and the alkylbenzenesulfonate, which mixture is the basis of a commercial formulation. The surfactant also may be a nonionic compound in the built formulation, for example, the polyalkoxy hydr'oxyamines as shown in US. Pat. No. 3,207,791 and the built formulations shown in this patent. The surfactant also may be a mixture of an anionic compound and a nonionic compound. Since cationic surfactants would react with polyphosphates, the polyphosphates are not used as builders in cationic surfactant formulations. Consequently, the instant invention is applicable to all commercial synthetic detergent formulations wherein sodium tripolyphosphate is utilized as a builder.

The following examples are provided for the purpose of illustrating specific embodiments of the invention but these are not to be construed as limiting the invention solely thereto.

EXAMPLE I The sodium salt of N-beta-hydroxypropyl taurine was prepared by adding 47.4 grams (0.815 mole of propylene oxide into a solution of 120 grams (0.815 mole) of the sodium salt of taurine in grams of water. The reaction of the propylene oxide with the taurine salt proceeds very rapidly and exothermically. Evaporation of the Water yields the theoretical amount of the adduct, i.e. 167.4 grams of the colorless crystalline solid sodium salt of N-beta-hydroxypropyl taurine. This compound was identified and its structure was established by infrared and Nuclear Magnetic Resonance spectrographic analysis. This compound was utilized without need for purification to produce the second condensation product to be described.

There was added to a three-necked flask fitted with a thermometer, mechanical stirrer and reflux condenser 31.2 grams (0.2 mole) of 1,2-epoxydecane, 41.0 grams (0.2 mole) of the sodium salt of N-beta-hydroxypropyl taurine produced as described. 10 grams water and 0.1 gram of sodium hydroxide. The two-layer mixture was stirred vigorously at C. until homogeneous and a test sample showed no Water-insoluble oil. This required approximately four hours. The reaction product was added to 200 ml. of normal hexane and 200 ml. of methyl alcohol. Evaporation of the methanol layer gave 69.7 grams of a tacky colorless solid. This amounted to 97 percent of the theoretical yield of the condensation product. The purity of the product was established by potentiometric titration with 0.1 N-hydrochloric acid whereby 98 percent of the theoretical amount of acid was required.

The product was identified as the sodium salt of N- beta-hydroxydecyl-N-beta -hydroxypropyl taurine. This compound was utilized without additional purification in the detergency tests to be described.

EXAMPLE II In a manner similar to that described for Example I 28.8 grams (0.16 mole) of 1,2-epoxydodecane (82 weight percent pure) was reacted with 32.0 grams (0.16 mole) of the sodium salt of N-beta-hydroxypropyl taurine (produced in Example I) in the presence of 10 grams of water and 0.1 gram of sodium hydroxide. The reaction was continued for four hours at 120 C. and the product partitioned between 200 ml. of methanol and 200 ml. of normal hexane. There was recovered a colorless tacky solid from the methanol layer by evaporation. This solid amounted to a yield of 96 percent of theoretical yield. The structure and identity of the compound was established in the manner employed in Example I, it was found to be the sodium salt of N-beta-hydroxydodecyl-N-beta-hydroxypropyl taurine. The potentiometric titration of the adduct consumed 95 percent of the calculated amount of 0.1 N hydrochloric acid based on the formula weight for C H NSO Na. It was found that the compound was freely soluble in water and gave copious foaming upon agitation.

EXAMPLE III In a manner similar to Example I, 13.1 grams (0.062 mole) of 1,2-epoxy tetradecane was reacted with 13.7 grams (0.067 mole) of the sodium salt of N-beta hydroxypropyl taurine together with grams of water and 0.1 gram of sodium hydroxide. The mixture was stirred for four hours at 120 C. and thereafter it was added to 100 ml. of hexane and 100 ml. of methanol. There was recovered by evaporation of the methanol a tacky colorless solid amounting to a yield of 86.5 percent of the theoretical yield of the adduct. The adduct was found to be the sodium salt of N-beta hydroxytetradecyl-N- beta hydroxypropyl taurine. It was identified in the same manner as described in Example I. Evaporation of the hexane layer gave a small amount of a colorless oil which by gas/ liquid chromatographic analysis was found to be unreacted 1,2-epoxy tetradecane. A potentiometric titration of the condensation product required 92 percent of the calculated amount of 0.1 N hydrochloric acid, showing that the product had a high degree of purity. The product was easily soluble in water giving a clear solution which foamed copiously on shaking.

During the potentiometric titration of the sodium salts of the N,N-disubstituted taurine condensation products produced in Examples I, II and III it was noted that with the addition of the aqueous hydrochloric acid and consequent formation of the acid form of the taurides a water-insoluble precipitate of the acid separates. This is an important effect with respect to use of the compounds in detergent formulations since during treatment in waste disposal plants these compounds can be separated as waterinsoluble compounds at the pH of conventional waste disposal facilities.

The foregoing examples have demonstrated the preparation of the novel compounds of this invention. The following examples are provided to show the utility of these compounds as replacements for the sodium tripolyphosphate in conventional detergent formulations.

EXAMPLE IV In order to show that the novel compounds of this invention such as those of Examples I, II and III can be used to replace a part or all of the polyphosphates in detergent formulations, a standard detergent formulation was prepared containing a sodium alkylbenzenesulfonate wherein the alkyl group was straight chain and ranged from 11 to 14 carbon atoms with an average of about 13.2 carbon atoms.

This standard detergent formulation had the following composition in weight percent:

Sodium tripolyphosphate40 Alkylbenzenesulfonate-ZO Sodium metasili'cate7 Sodium sulfate32 Sodium carboxymethyl cellulose1 This built formulation was modified by replacing all of the sodium tripolyphosphate with the preferred combination of 25 weight percent of the diepoxide-taurine sodium salt condensation product and 75 weight percent sodium carbonate. These detergent formulations were tested in a standard Launder-Ometer apparatus.

The procedure and method of calculating detergency values differ in minor detail from that shown in Carbon Soil Removal, P. T. Vitale et al., Soap and Chemical Specialties, vol. 32, No. 6, pp. 41-44 (June 1956), and are described below. The Launder-Ometer consists of a spindle mechanism rotating in a hot water thermostated bath. Mason jars 1 pint capacity containing detergent, water, soiled cloth, and hard rubber balls for agitation are rotated on the spindle mechanism for a set time at a set rate in the hot water. The degree of cleaning is determined and the resulting numbers are the detergency values. These values are correlated with a standard anionic detergent having an arbitrarily assigned detergency value.

The detergency tests are conducted in the following manner:

The new cloth is cut into 4-inch wide strips across the bolt. Six strips are rolled up together and extracted with 500 cc. of acetone for 6 hours in a Soxhlet extraction apparatus. The strips are then removed and rinsed 3 times in distilled water, air dried until just barely damp, ironed until completely dry, and then placed in a 200 F. oven for 3 hours. At the end of this time, they are removed from the oven and set in a dessicator in a temperature and humidity controlled room.

The strips of cloth are soiled with the following composition:

Commercial hydrogenated vegetable oil (trademarked Crisco) 0.9 U.S.P. grade mineral white oil 3.1 Lampblack 1.0

Carbon tetrachloride500 ml.

The hydrogenated vegetable oil, mineral white oil and lampblack are mixed with sufiicient carbon tetrachloride to just dissolve the oil and fat. The concentrated soil slurry is then passed through a small, hand-operated homogenizer and the balance of the carbon tetrachloride added. About 200 ml. of soil is placed in a nine-inch evaporating dish and a strip of the cloth is passed through this rapidly and smoothly three times. The cloth is hung to dry at room temperature for 2 hoursil5 minutes and is then cut into 2-inch by 4-inch swatches and read photometrically. The photometer is calibrated against a magnesia block with the standard equal to 100.

One-pint Mason jars are washed and set in the Launder- Ometer rack. They are each filled with 6 ml. of 5 percent by weight solution of the above-mentioned built compositions, l0 three-eighth inch diameter hard rubber balls, one soiled swatch, and enough 180 p.p.m. hardness water to make ml. of solution. The final concentration of the built composition is 0.3 percent. The jars are capped, set on the spindle, and rotated at 40-42 r.p.m. for 20 minutes at F. The jars are immediately removed, the height of the foam above the detergent solution in each jar is immediately noted (following one quick inversion of each jar), and the svslr(atches are dried on paper and photometer readings ta en.

The detergency is calculated in the following way:

Raw detergency= X 100=L where R=photometric percent reflectance of the washed cloth, S: photometric percent reflectance of the soiled cloth, V=photometric percent reflectance of the virgin cloth, S usually ranges from 18 to 24,

V is practically a constant at 87,

R varies from 4080.

The L value is then related to a factor to give the final detergency:

& 's

a standard value by where:

S =the arbitrary detergency of the standard, L the L (raw detergency) value for the standard which is always run concurrently with the material being tested.

An arbitrary detergency (S of 70 is assigned to a commonly used commercial anionic detergent which is employed as the standard. The results of these tests are shown in Table I.

These data demonstrate that the diepoxide-taurine sodium salt condensation products when combined with an inorganic salt buffering agent can be utilized as replacements for the sodium tripolyphosphate with the N- beta-hydroxydodecyl compound being optimum.

A second series of tests were made utilizing combinations of the condensation products. The Launder-Ometer test results are shown in Table II.

TABLE II Sodium tripolyphosphate replacement compounds Detergency Foam inche Sodium tripolyphosphate (comparison standard)- 12.5 Weight percent N-beta-hydroxydecyi-N -betahydroxypropyl taurine sodium salt 12.5 weight percent N-beta-hydroxydodecylhydroxypropyl taurine sodium salt" 75 weight percent sodium carbonate 12.5 weight percent N-betahydroxydodecyl-N-betahydroxypropyltaurine sodium salt 12.5 weight percent N -beta-hydroxy-tetradecyl-N- beta-hydroxypropyltaurine sodium salt 75 Weight percent sodium carbonate 12.5 Weight percent N -beta-hydroxydecyl-N-beta hydroxypropyltaurine sodium salt 12.5 Weight percent N-beta-hydroxytetradecyLN- beta-hydroxypropyltaurine sodium salt 75 Weight percent sodium carbonate 12.5 Weight percent N -beta-hydroxydodecy beta-hydroxypropyltaurine sodium salt 6.25 weight percent N-beta-hydroxytetradecyl-N- beta-hydroxypropylt-aurine sodium salt 6.25 Weight percent N-beta-hydroxytetrahexadecyl- N-methyl taurine sodium salt 75 Weight percent sodium carbonate These data show that there is an advantage to be obtained utilizing a mixture of the novel compounds of this invention in combination with sodium carbonate as the inorganic salt buffering agent to replace sodium tripolyphosphate in detergent formulations.

Similar results are obtained when sodium metasilicate, sodium bicarbonate, sodium acetate or ammonium acetate are substituted for the sodium carbonate in the compositions of this example.

We claim:

1. A built polyphosphate-free synthetic detergent composition consisting essentially of:

(a) a sodium alkyl benzene sulfonate wherein said alkyl group is straight chain and is in the range of from 10 to 14 carbon atoms,

(b) a combination consisting of (1) an inorganic salt bufiering agent selected from the group consisting of sodium bicarbonate, sodium acetate, ammonium carbonate and sodium bicarbonate and (2) the condensation product having the formula wherein R is an alkyl radical having from 1 to 16 carbon atoms, R is hydrogen or an alkyl radical having from 1 to 15 carbon atoms, the sum of the carbon atoms in R plus R ranges from 2 to 16, R is a methyl, ethyl or propyl radical and M is ammonium or alkali metal ion with the weight ratio of condensation product to inorganic salt in said combination ranging between 1:3 and 1:7, said combination of inorganic salt and condensation product being in the range of from 35 weight percent to 40 weight percent of said detergent composition, (c) sodium sulfate, (d) sodium metasilicate, and (e) sodium carboxymethyl cellulose. 2. The composition according to claim 1 wherein R has from 10 to 16 carbon atoms and R is hydrogen.

3. The composition according to claim 1 wherein R 40 has from 10 to 16 carbon atoms, R is hydrogen and the inorganic salt is sodium carbonate.

References Cited UNITED STATES PATENTS 3,474,038 10/1969 Sepulveda etal 252-137 2,830,082 4/1958 Sexton 6t a1. 260- 513 3,459,666 8/1959 Weichbrodt et al. 252 137 FOREIGN PATENTS 701,363 1/1965 Canada 260-513 LEON D. ROSDOL, Primary Examiner M. HALPERN, Assistant Examiner US. (:1. X.R.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION May 18, 1971 Patent No. 3, 579,457 Dated Inventor(s) Robert M. Lincoln and Joseph A. Meyers III and Richard W. Sauer It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In Claim 1, column 8, line 14 "bicarbonate" should read --carbonate-- Signed and sealed this 214th day of August 1971.

(SEAL) Attest:

EDWARD M.FLETCHER, JR. WILLIAM E. SCHUYLER, JR. Attesting Officer Commissioner of Patents 

